import React, {Component} from 'react'
import PubSub from 'pubsub-js'

export default class Second extends Component {
  componentDidMount() {
    // 开启定时器
    setTimeout(() => {
      PubSub.publish('study', {a: 1})
    },2000)
  }

  render() {
    return (
      <div>

      </div>
    )
  }
}
